Mostly in the last three levels where you kept having to do the really precise parts only to get to new territory and die because you didn't know what to do exactly. Compare it to Getting over it where you have to risk falling if you want to gain information on how you climb, but after falling it then takes a lot of precision to get back to where you were.
For example, in the third to last level you finally make it through the frustrating first bit where you keep jumping into the spikes, only to grab one wrong firefly, meaning you have to do the first bit again.
Another way it sometimes feels like a rage game is the way you have to hold full right in a lot of jumps. If you play a Mario game for example there are barely any jumps that you have to fully commit to to only barely make it. In fact, in Mario games almost all jumps are possible to make without running. In your game these jumps feel rather similar to rage games where after having commited to a move you have to watch in pain how you're just short. In some jumps the double jump helps though.
Thanks for reading!